Transmission unit



Sept. 13, 1949. S J. 5. SHARPE TRANSMISSION UNIT 2 Sheets-Sheet 1 Filed Jan. 24, 1946 TRANSMISSION UNIT Filed Jan. 24, 1946 2 Sheets-Sheet 2 t Patented Sept. 13, 1949 TRANSMISSION UNIT John S. Sharpe, Haverford, Pa.; Catharine D. Sharpe, executrix of the estate of said John S. Sharpe, deceased, assignor to The Franklin Institute of the State of Pennsylvania for the Promotion of the Mechanic Arts, Philadelphia,

Pa., a corporation 1; Application January 24, 1946, Serial No. 643,040

This invention relates to transmission devices, and a primary object of the invention is to provide a transmission unit of novel and desirable structural and functional characteristics.

A more specific obj ectof 'the invention is to provide a reverse gear unit of compact, rugged, and relatively simple form affording a, direct drive connection between the input and output ends of the unit, together with a reverse drive of the same or different ratio as may be required.

In the attached drawings:

Fig. 1 is a sectional view of a preferred embodiment of my invention, and

Fig. 2 is a sectional view illustrating a modification within the scope of the invention.

With reference to Fig. l, the unit therein i1- lustrated comprises a relatively fixed casing I within which is journaled a pair of shaft elements 2 and 3 respectively. The element 2 is journaled at one end in bearings 4-4 and at the other end in a bearing 5. The element 3, which is coaxial with the element 2 and embraces the latter, is journaled in part upon the bearings 4-4 and in part upon a bearing 6. In this matter the shaft elements 2 and 3 find a mutual support in the bearings 4 and a common support in the housing through the medium of the bearing 6.

In the present instance the shaft 2 extends continuously through the unit and, intermediate its ends, includes a crank I. The shaft is made in I two longitudinal sections of which one section comprises a pin element 8 and the other section a sleeve 9 which receives the pin 8 as illustrated to form the crank I. The two parts are united by a nut II which is applied to the threaded extremity of the pin 8 and which seats against an end surface of the sleeve 9.

Journaled on the crank I is a planetary elemerit I2 in the form in the present instance of a composite gear including an external element I3 and an internal element I4. Anti-friction bearings I5 are provided between the crank 'I and the composite gear. Obviously since the composite element I2 is journaled on the shaft for rotation about an axis eccentric to the shaft axis, rotation of the shaft will cause the gear to move in an orbital path concentric with the shaft.

The gear I3 meshes with an internal gear I6 on the casing I; and the internal gear I4 meshes with a gear I'I secured to the inner end of the shaft 3. In the present instance each of the shafts 2 and 3 is provided with a clutch, I8 and I9 respectively, by means of which these shafts may be connected selectively to a source of power, or to driven elements, as the case may be.

2 Claims. (Cl. 74-804) In operation and assuming that power is ap-i plied through the clutch I8 to the shaft 2, the clutch I9 being disengaged, the power will be transmitted directly through the shaft 2, and if the power is withdrawn from the other end 2a of the shaft 2, the speed ratio at the input and output ends of the unit is necessarily one to one. If it is desired to reverse the direction of rotation of the shaft, the clutch I8 is disengaged and the clutch I9 engaged, with the result that the drive is through the shaft 3 and pinion I! to the internal gear I4. The gear I3 of the composite element I2 then reacts with the relatively fixed internal gear I6 to turn the shaft 2, on which the element I2 is journaled as described, in the reverse direction and at the same one to one ratio. The speed ratio in this instance is a function of the relative diameters of the gears I'I, I4, I3, and I6 and may be varied by exchanging the gears,

f) in pairs, for others of differing size.

'- spond to the shafts 2 and 3 of the previously described embodiment. Similarly, the shafts are provided with clutches, 24 and 25 respectively. In this instance the composite gear 26 is journaled on an eccentric 2'! on the shaft 2 3, said 1.1 gear being thereby movable in an orbital path eccentric to the common axis of the shafts 22 and 23. The gear element 28 of the composite gear 28 meshes with an internal gear 29 on a part 3! of the relatively fixed structure of the unit. The internal gear element 32 of the composite gear 26 meshes with a gear 33 secured to the shaft 22. The eccentric 2'! is counterbalanced in this instance b a counterweight 34 on an arm 35 of the shaft 23.

In operation, if the clutch 24 is engaged so as to connect the shaft 22 with a source of power, power being withdrawn from the other end 22a of the shaft 22, the input to output ratio of the unit is unity. there being a direct drive through said shaft. If the clutch 25 is engaged, the drive is through the shaft 23 and eccentric 21 to the composite gear 26, said gear reacting with the relatively fixed internal gear 29 to drive the gear 33 through the internal gear element 32. The

' shaft 22 in this case will be rotated in the reverse direction at approximately the same one to one ratio.

It is to be noted that in each embodiment, if one of the coaxial shafts is driven in one direction; 'the other shaft will be glriven in 313116 opposite direction; and with the vgear ratios shown the rotation of the shafts will be at the same rate. Also, if power is applied to the end 20; of the shaft 2, or to the end 22a of the sl aft 22, the shafts 3 and 23 will be rotated in the opposite direction and at r thezsa m e rate. this latter respect the unit may l ;e.'--u sedasa V fixed ratio split contra-drive.

I claim:

1. In a reverse gear unit,-ashaft-one-en-d-ef which constitutes the output element of the unit, a. second shaft coaxial wit lr andceinjoracing the shaft first-named, a composite planetary gear journaled eccentrically on said first-named shaft for movement in a planetary path concentric with the shafta isaa rela v yfi dzaeamnesiin i h e e emen efi a lane yea gea on aiiiew-m1 ha r-zn new than th eaa el men {of esa planet y an :me n 1? la plying power to said shafts selectivel -y tathereby efiefl li se e i e1mtat no h r u u shaf in pnqs tesiir ct ens, i In .\a;. reverse gear i unit, a ishaft one end of 4 v which constitutes the output element of the unit, a second shaft coaxial with an embracing the shaft first-named, a composite planetary gear having internal and external toothed elements jou-rnaled ;OCnt1iCa1ly, -Qpsid figst r iamed shaft V formovement in a planetary path concentric with the shaft axis, a relatively fixed internal gear meshing with an external gear element of ding withan internal gear element of said plane sai d planetary a gear on said second shaftmeshg 7 ammcans fcaap of the-outpuhshait in opposite directions.

JOHN s. SHARPEJ :REFERENCES CITED The ,-fol1owing;-reterences are of record in the plying power to said shaft selectivel to there y efiect a selective rotation V: 

